Revert "bridge: Allow forward delay to be cfgd when STP enabled"

8a921265 · Vlad Yasevich <[email protected]> · 2015-11-10 06:15:32 -05:00

This reverts commit 34c2d9fb0498c066afbe610b15e18995fd8be792.

There are 2 reasons for this revert:
 1)  The commit in question doesn't do what it says it does.  The
     description reads: "Allow bridge forward delay to be configured
     when Spanning Tree is enabled."  This was already the case before
     the commit was made.  What the commit actually do was disallow
     invalid values or 'forward_delay' when STP was turned off.

 2)  The above change was actually a change in the user observed
     behavior and broke things like libvirt and other network configs
     that set 'forward_delay' to 0 without enabling STP.  The value
     of 0 is actually used when STP is turned off to immediately mark
     the bridge as forwarding.

Signed-off-by: Vlad Yasevich <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Commit: 8a921265e2cd31e61a0c2eda582af54c5bfef897
Parents: a31d82d8

Changes

1 files changed · +9 −4

File	Status	Add	Del	Content
net/bridge/br_stp.c	modified	+9	−4	View file

net/bridge/br_stp.c

View file

diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index 80c34d7..f7e8dee 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c
@@ -600,12 +600,17 @@ void __br_set_forward_delay(struct net_bridge *br, unsigned long t)
 int br_set_forward_delay(struct net_bridge *br, unsigned long val)
 {
 	unsigned long t = clock_t_to_jiffies(val);
-
-	if (t < BR_MIN_FORWARD_DELAY || t > BR_MAX_FORWARD_DELAY)
-		return -ERANGE;
+	int err = -ERANGE;
 
 	spin_lock_bh(&br->lock);
+	if (br->stp_enabled != BR_NO_STP &&
+	    (t < BR_MIN_FORWARD_DELAY || t > BR_MAX_FORWARD_DELAY))
+		goto unlock;
+
 	__br_set_forward_delay(br, t);
+	err = 0;
+
+unlock:
 	spin_unlock_bh(&br->lock);
-	return 0;
+	return err;
 }